Ladder Technical Description

This document is a reference document for those of you who want to know how your new rank came about. If you cursor over your rank and click on “view” you will see the details of the calculations. You can do that with other players as well. Your comments and suggestions are welcome.

The main purpose of this tournament is to allow players to enjoy the game and play with others of the same skill level.

This particular tournament has over 50 players enrolled. Players have to sign up to play each week as only a limited number of courts are available.

In this case, 5 courts are available and 2 time slots.

New rankings are calculated on the basis of previous rankings and scores. These are subject to fine tuning change.

  1. set @win = -3 or -4; #winner of each group
  2. set @lose = 2.4; #loser of each group
  3. set @lastlose = 3.4; #overall bottom player
  4. set @mid2nd = -1.8; #players who comes in 2nd in their group
  5. set @mid3rd = 0.3; #players who comes in 3rd or 4th in their group
  6. set @mid4th = 1.4; #players who comes in 4th in their group of 5
  7. set @noshow = 0; #players who did not play
  8. set @subst = 0; #substitute and spare players

Note the decimal in each one of these. They do not affect the rankings but do serve to indicate where the player finished within the group.  (for a group of 4, .4 is in last position, .3 in second from the last, .2 (-1.8) in second position).

We have slightly “tweaked” ranking points for players who come in first in their group. If they were 3rd or 4th in their group and they win that group then we take 4 ranking points from them (they go up the ladder). Otherwise we take 3 ranking points from the winners, as before. This applies to people in the first group as well, you cannot do better than 1st place (no place 0 or -1).
After the computer calculates ranking points the convener  examines the resulting rankings and can make slight changes in the ranking points to alter rankings. This allows for the tweaking of players who were either ranked too high or too low when they started. Remember, the goal of the ladder system is to allow players to play with players at the same level and to make the playing experience as pleasant as possible.

The above has been copied from the computer program which calculates the new rankings. These are explained below:

All the numbers represent ranking points and are numbers which are added to the player’s previous rank. These become calculated ranks and only serve to put the players in order, from lowest calculated rank to highest calculated rank. Ties are resolved by placing the player who played or who had the lowest previous rank first.

Thus,

the winner of each group gets -3 or -4 added to their ranking points (their ranking improves). This becomes a calculated rank and must not be below 1;

the player in last position in the last group gets +3 added to their previous rank (their ranking worsens);

the player in last position in each group gets +2.4 added to their previous rank (their ranking worsens);

the player in 2nd position gets -.8 added to their previous rank (their ranking improves);

the player in 4th position gets +1.4 added to their previous rank (their ranking worsens);

players who do not play in a particular session get +0 added to their previous rank (their ranking worsens). This prevents players from choosing not to play to protect their ranking. The .6 is added to break ties in ranking points with players who have played that week.

Players who are spares or who play as substitutes in groups that do not have a full complement of players have 0 added to their ranking (their ranking stays the same). Players who had a substitute play for them are assigned a negative score (on the scoresheet) and become “no -shows”.

Other players may choose to join the ladder and their calculated rankings become the ranking assigned to them by the convener based on reported playing levels, subjective evaluations or just plain guesses. Their calculated ranking becomes this ranking +0.

The convener then looks at all the rankings and has a final say in the resultant “calculated” rankings. The convener then places the desired calculated rank in the override column (on the website page) and this override column becomes the final calculated rankings column.

All players are then placed in the order of their calculated rankings, ties resolved by their previous rankings. New rankings are then determined by player’s resultant positions, from 1 to the number of players registered for the ladder.

Please note that this kind of ranking system may result in apparent anomalies. For instance, a better ranked player may not get as many points in his group as a lower ranked player but because of the difference in their beginning ranks the movement in the ladder may not be enough to move the player with more points in that group above the player that had fewer points. This prevents large movements that may just be accidental to one session.

The next playing session is set up with players who register for the session. They are then assigned to groups in the order of their rank. Thus, the first players go in the first group based on their rank. Those may not be the top players in the ladder, some of those top players may not have registered to play in that session.

The convener then assigns courts and times. Where possible players who have indicated that they travel together are put in the same time slot. This is not always possible.

At the end of each playing session scores are entered into the computer and the whole process is repeated.

We know this may be a bit complicated to understand and are open to suggestions. If you feel the numbers above should be “tweaked” please suggest the new numbers you would like to see and your reasoning behind those new numbers. If you  can think of another way of doing the rankings within the club, please explain how you would do it, detailing the steps in the whole process. If you can say it, we can program it.

For the techies among you, this is all programmed in a single PHP and mysql function.